I just wanted to add that a good book which covers the collecting practices of Cecil Sharp, Baring-Gould etc. is 'Fakesong', by Dave Harker.
I think you'd have to say Peter Kennedy was also a pioneer and probably had the faults of a pioneer. Should he have known better with some of the things he is alleged to have done? Maybe - maybe not.
It all comes down to your standards of ethics. In an area like collecting, ethics evolve. These days, if you're attached to a university and want to record people playing folk music you usually have to get signed permission from them. This is because people's rights are seen as more important (+ there are liability issues).
We should learn from the mistakes of past collectors and those (now) cringe-worthy actions - but we shouldn't completely judge them by our contemporary standards. Nonetheless, we can learn only by knowing the details. Perhaps Rod's article seems a little harsh at first reading, but I'm certain his intentions are good. After all, he's doing an important job supporting serious writing about traditional music, especially about the role of traditional singers and musicians, who undoubtedly got short shrift by earlier generations of collectors.